The herb echinacea, utilized by Native Americans for centuries, is a popular remedy for preventing or reducing the severity of the common cold. Hundreds of studies, primarily conducted in Germany, have provided information on the herb's chemical and pharmacological characteristics, yet few studies have actually proven its ability to reduce cold severity.

To evaluate the effectiveness of dried, whole-plant echinacea capsules for early treatment of the common cold, approximately 150 students in the early stages of a cold were divided to take either a placebo or echinacea. The echinacea group took an encapsulated mixture of unrefined echinacea root and herbs in one-gram doses, six times on the first day of illness and three times per day on subsequent days, for up to 10 days. The placebo group took capsules containing alfalfa, which has no proven ability to boost the immune system, at the same frequency.

No difference was observed between the echinacea and placebo groups for any cold symptoms, including cough, sore throat, runny/stuffy nose or headaches. Average duration of the cold was approximately six days in both groups. Also, cold severity measures were "nearly identical" in those taking echinacea or placebo pills.

Although this is certainly not the last word on echinacea, since some previous research contradicts this study, it shows that otherwise healthy people might not obtain as much benefit from the herb as older adults who have frequent colds or viral illnesses. The best advice is to reduce your chances of getting a cold in the first place: wash your hands frequently with soap and water, and boost your immune system by eating lots of fruits and vegetables and getting plenty of sleep.